US2164812A - Constant-capacity feeder - Google Patents

Description

July 4, 1939. E. v. FRANCIS ET AL 2,

CONSTANT CAPACITY FEEDER Filed June 10, 1936 s Sheets-Sheet 1 v [NI/ENTORS EARLE V FRANCIS,

AND

JAMES A. FLINT,

A TT'Y July 4, 1939. a. v. FRANCIS ET AL CONSTANT CAPACITY FEEDER Filed June 10, 1936 5 Sheets-Sheet 2 INVENTORS: EARLE V. FRANCIS,

JAM ES XfFLIN'I;

ATT'Y July 4, 1939. E) v FRANCIS AL 2,164,812

' CONSTANT CAPACITY FEEDER Filed June 10, 1936 5 Sheets-Sheet 3 6' /NVEN7'ORS EARLE V FRANCIS,

I HND JAMES A. FLINT, ByflZ I AT 'Y July 4, 1939.

a.- v. FRANCIS 51* AL CONSTANT CAPACITY FEEDER 5 Sheet$-$heet 4 Filed June 10, 1936 //VVE/YTOF\ 5.' EARLE \A FRANCIS,

AND JAMES A. FLINT,

m M I ATT Y Jul 4, 1939. E. v. FRANCIS ET AL CONSTANT CAPACITY I FEEDER Filed June 10, 1936 5 Sheets-Sheet 5 f/vvE/vToRs: EARLE V FRANCIS, AND JAMES A. FLINT,

- ATT'X 8L is Patented July 4, 1939 UNITED STATES PATENT OFFICE 2,164,812 I CONSTANT-CAPACITY FEEDER Earle V. Francis and James A. Flint, Columbus,

Ohio, assignors to The 'lraylor Vibrator Company, a corporation of Colorado Application June 10, 1936, Serial No: 84,496

, 21 Claims. (01. 221-118) materials at a relatively slow and constant rate,-

and which is entirely automatic in its operation.

Another object of the invention is to provide a constant capacity feeder, the capacity of which may be variably determined and which will oper ate entirely automatically to deliver'material at a constant rate and in relatively small quantities. Still another object is to provide a constant capacity feeder in which the starting period, 7

which is a transient period during which the rate of feed is not constant, is reduced to a minimum, thereby providing a device which has a relatively short correction time.

Another object of theinvention is to provide a constant capacity feeder. which may be of either the constant weight or the constant volume type.

Another object of the invention is to provide an improved control means and control circuit for a feeder.

Other objects of the invention will appear hereinafter, the novel features and combinations being set forth in the appended claims,

In the accompanying drawings,

Fig. l is a side elevational view of the device comprising my invention; 1

Fig. 2 is a plan view of the device of Fig. 1 with parts removed for clearness;

Fig. 3 is a sectional elevational view taken along a longitudinal axis of the device of Figs. 1 and 2; Fig. 4 is an elevational view of the control switches with the cover plate of the switch box Fig. 5 is a transverse sectional view taken on the line 5-5 of Fig, 1 looking in the direction of. the arrows;

Fig. 6 is a transverse sectional view taken on the line li6 of Fig. 3 looking in the direction of the arrows;

Fig. 7 is a front elevational view of the control mechanisms shown with the cover plate of the control box removed and eliminating the electric conductors in the interest of clearness;

Fig. 8 is an end elevational view of the control box with part of the end wall broken away to show a portion of the internal mechanism there- Fig. 9 is a sectional of the arrows;

Fig. 10 is a wiring diagram for the view of a detail and taken L on the line 9-9 of Fig. 8 looking in the direction control system which is contained within the control box illustrated in Fig. 7;

Fig. 11 is a wiring diagram of the circuits for the conveyor motors;

Fig. 12 is a wiring diagram for the control switches of Fig. 4; and

Fig. 13 is a sectional elevational view showing a modified form of the invention.

Many problems arise in which it is desirable to feed a constant weight or constant volume of material at a relatively slow rate. Examples of this are found in the treatment of drinking water, carried on by municipalities in which chemical salts are desired to be fed at a uniform slow rate to the water. The invention herein disclosed provides a completely automatic system for feeding such chemical salts to a stream or container of water and provides means whereby the'rate of delivery may be adjusted as desired. It will be evident that the invention is capable of more general application, theexample given only being a typical illustration.

Referring particularly to Figs. 1, 2 and 3 of the drawings, our invention comprises a main frame 20 formed of longitudinal and transverse angle members 2i provided with adjustable legs 22 whereby the said main frame 20 may be leveled. Adjacent its rear end, the main frame carries a supporting stand 23 which may also be formed 'of appropriate angle members 24 and an appropriate supporting top plate 25. Upon said stand 23 is mounted a vibratory conveyor 26 which preferably takes the form disclosed and claimed in the copending application of James A. Flint and Arthur D. Holt, Serial No. 17,244, filed April 19, 1935.

Briefly described, said vibratory conveyor 26 comprises a trough type deck 2'! supported away from a base 28 by cantilevers 29 which make an acute angle with the plane ofsaid deck 21. Ad-

'jacent its rear end, the deck 21 carries an armature '30. Adjacent the rear end of the base 28 is mounted a field structure 3| supported by a bracket 32. The field structure 3| may be energized in a manner, hereinafter described in more detail, to impart vibratory motion to the deck 21,

which,'due to the angular relation of the cantilevers 29 will convey material to the right, as vewed in Fig. 1, at a rate dependent upon the amplitude of vibration of said deck 21.

Positioned above the deck 21 is a feed hopper 33 provided with an adjustable gate mechanism 34, and supported away from the base 28 by -arms35. The base 23 preferably sits on the stand 23 and is supported by rubber shoes 36.

. In the operation of the vibratory conveyor 26 some vibration will be transmitted to the base 28 which, in turn, will be transmitted through arms 35 to the hopper 33. This will insure a continuous feeding of the material in the hopper 83 to the deck 21 and prevent arching of material in said hopper. The deck 21 is positioned to feed material into a scale device, hereinafter described in more detail.

Adjacent the front part of the main frame is an upstanding support 31 formed. by a pair of spaced vertical angle members 38, 38 connected together across their tops by a transversely extendingangle member 38 (see Fig. 3). Reinforcement of the support31 and the stand 23 is provided by a pair of longitudinally extending angle members 48 which are connected together at their forward ends by a transversely extending plate 4|.

As best seen in Figs. 2, 3 and 6 of the drawings, adjacent each end of the transverse angle member 38 there is provided an L-shaped bracket 42 which is rigidly attached to the angle member 38 as by nuts and bolts 43, and which provides a fulcrum bearing 44 'for a fulcrum or beam type scale mechanism, hereinafter described in complete detail. Mounted for free pivotal movement on the fulcrum bearings 44 provided by the brackets 42, is a beam type scale mechanism 45. Said scale mechanism 45 comprises a scale frame formed by a pair of longitudinally extending side plates 46 which may be in the form of castings which are attached together at one end by a transversely extending plate 41 which forms the bottom plate of a belt type conveyor generally designated by the character 48. Atthe other end, said side 'plates 46 are connected by a transversely extending bed plate 48 which forms the support for a driving electric motor 58 and a speed reduction mechanism 5| for the conveyor 48.

As best seen in Figs. 1, 2, 3 and 6, the scale mechanism 45 will be pivotally supported upon the fulcrum bearings 44 by a transversely extending square shaft I58 which is removablyattached to the side plates 46, as by set screws '|5| (see Fig. 6). The lower knife edge of the square shaft I58 will ride in the fulcrum bearings 44 at each end of said shaft I58. As clearly illustrated in Fig. 6 of the drawings, the fulcrum bearings 44 will be provided with an upstanding inner end wall 52 which extends into a notch 53 .on the square shaft I58 thereby to restrict lateral a tail drum is mounted-upon shafts 5s and 51.

respectively, the former of which is carried by appropriate journal bearings 58, 58 formed intee grai with the side plates 46, 46, and the latter of which is carried by adjustable journal boxes 58 slidably mounted in appropriate guideways 88 formed in the side plates 46. Belt tensioning and Journal box adjusting mechanism 6| in the form of a set screw may be provided to cooperate with the journal boxes 58 toprovide for adjustment of the tail drum 55. Mounted upon the two drums 54 and 55 'is a continuous belt 62 Preferably made of fabricated rubber material.

At one en'd, the shafts 56 and 51 carry sprockets 83 and 54 respectively, which areof equal size and which are connected by a chain 65 (8 F18- 2). In addition, the shaft 56 carries a sprocket 61 which receives a chain 68 driven by an appropriate sprocket 68 carried on a shaft 18 which extends from the speed reduction mechanism 5|.

It may be mentioned that said speed reduction mechanism 5| is driven from. the electric motor 58 through an appropriate coupling unit 1| and said speed reduction mechanism 5| will be effective toreduce appreciably the rate of rota tion of shaft 18 as compared with the rate of rtation of the drive shaft of motor 58. In actual practice a ratio of 1600 to 1 has been employed.

In order to maintain proper tension on the chain 68, ,we may also provide an adjustable chain tensioning device 12 (see Figs. 2 and 3). It may also be mentioned that the sprockets 61 and 68 are of different size and a different drive ratio between the motor -58 and the conveyor 48 may be effected by reversing said sprockets 61 and 68.

In addition to those elements previously described, the conveyor 48' comprises a hood formed of side plates 15, 15, the bottoms of which are provided with wipers 16, 16 (see Fig. adapted to wipe the upper run of belt 62 and prevent lateral spilling of material from said belt 62. The side plates 15, of said hood are supported from the side plates 46, 46 of the scale'mechanism 45 by appropriate brackets 11 and cooperating machine screws and by machine screws 18 (see Fig. 3) which extend through the flanges 0f the front spacer plate 65 of a guiding chute 18 of said scale mechanism 45, and into appropriate threaded apertures in the side plates 46. The chute 18 provides an appropriate guide for the granular material which is conveyed by the conveyor 48 and discharged over the head drum 54. The discharged material will fall from the chute 18. into a stationary chute 88 carried byappropriate brackets on the main frame 28 and angle members 48.

Extending transversely across the tops of the side plates 15 is a top cover plate 8|. Adjacent their rear ends the side plates 15 carry a sloping back plate 82 which terminates adjacent the belt 62 and at a position directly above the axis of shaft 51. As clearly seen in Fig. 3 of the drawings, the top plate 8| and back plate 82 c0- operate to provide an opening 83 through which the deck 21 of the vibratory conveyor 26 may extend. It is to be noted that said opening 83 is of suflicient size to permit an appreciable amount of pivotal movement of the scale mechanism without contacting said deck 21.

It may also be noted, particularly by referring to Fig. 1 of the drawings, that the angle members 48 carry a pair of adjustable stop means 85, 85 adapted to restrict the pivotal movement of the scalemechanism 45 inone direction by .contacting brackets 86, 86 formed integral with the side plates 46, 46. A tilting movement of the scale mechanism 45 in the other direction is effected by a pair of adjustable stop means 81, 81 carried by brackets 88, 88 rigidly attached to angle members 48.

In order to provide for the balancing of the scale mechanism 45 when'it is unloaded, we provide an adjustable weight 88 supported by a pair of longitudinally extending smooth shafts 9|, 8| (see Fig. 2) which are carried by a transversely extending plate 82 which extends between side plates 46 and is rigidly attached thereto, and by a transversely extending'plate 83 formed integral with the plate 65. (Fig. 3.) The weight .88 is provided with a pair of smooth apertures which fingers H and H6 are adapted to extend into slidably receive the shafts 9|, 9| and provide a free sliding support for said weight 90. Said weight 90 is also provided with an additional aperture which is screw threaded to receive a threaded shaft 94 also carried between the plates 92 and 93 and mounted for free rotation with respect thereto. An operating knob 95 (Fig. 3) is provided to afford rotation of the shaft 94.

- It will be obvious that rotation of the shaft 94 While not generally so employed, the adjustable weight 90 may also be employed to vary the of the constant capacity feeder.

feeding rate of the constant capacity feeder. It is preferred, however, that an additional adjustable weight be provided for this purpose, which will nowbe described. Said additional adjustable weight mechanism comprises an up-' standing bracket 96 carried by one of the side plates 46 and a bracket 91, also carried by said one side plate 46. Between said brackets 96 and 91 extends a weight beam 98 upon which is slidably mounted an adjustable weight 99 provided with a set screw I00. The weight 99 may be adjusted so as to determine the rate of feed of the constant capacity feeder and by screwing the set screw I00 home, the rate of feed will be insured to be constant.

The beam 98 is so mounted that a horizontal plane through the center of gravity of the weight 99 preferably passes through the fulcrum 'point of the scale mechanism 45 with the result that the arm 98 may be calibrated so that equal movements of said weight 99 from the fulcrum point will produce equal increases in the rate of feed A suitable scale 98' may be provided in accordance with such calibration. It can readily be seen by referring to Fig. 1 that the farther the weight 99 is adjusted away from the fulcrum 44, the greater will be the weight of the material fed at a con- I stant rate from the conveyor belt 62.

In order to control the rate at which material is fed by the vibratory conveyor26 to the beltmounted a pair of mercury tube switches I02 and I03. (See Fig. 4.) Each of said'tube switches I 02 and I03 comprises a glass tube I04 within which is a small amount .of mercury I05 into which extends a stationary contact I06. A spring mounted movable contact I01 carries a magnetic member I08, such as a plate of iron, which maybe attracted by a magnet to pull the contact I01 into the mercury I05 to close said switch I02 or I03.

Appropriate leads I09, IIO, III and H2 are provided for the switches I02 and I03. The first two mentioned leads are provided for switch I02 and the last two for switch I03. Said leads I09, IIO, III and H2 extend to appropriate connecting posts carried kw an insulated terminal block 3, mounted within the switch box IIII.

. Associated with one of said side plates 46 an rigidly attached thereto, is an inverted U-shaped bracket II 4 carrying a pair of spring fingers. I I5 and H6 which may be adjusted by adjusting screws Ill and 8, respectively. The spring apertures I I9 and I20, respectively, of the switch box IN, and carry at their ends permanent magr nets I 2I and I22, respectively. Also carried by the switch box- IOI. are adjusting screws I23 and I24 which cooperate with the spring fingers I I5 and 6, respectively, to limit their movements. It will be evident that if the scale mechanism 45 tilts about its fulcrum in a clockwise direction, the permanent magnet I22 will be brought in proximity to the mercury tube switch I03 and will be effective to attract the plate I08, thereby to close the contacts of said switch I03. -A counter-clockwise tilting of the scale mechanism 45 will produce movement of the permanent magnet I2I in proximity to the mercury tube switch I02 with the' consequent attraction of the plate I08 thereof and the closing of the contacts of said switch I02. When the scale mechanism 45 is in a condition of equilibrium the contacts of both switches I02 and I03 will be open. It is thus manifest that the circuits to switches I02 and I03 may be controlled by the balanced or unbalanced conditionof the scale mechanism 45, and when an unbalanced'condition is realized one or theother of said switches will be closed, depending upon the direction of unbalance.

It may be 'mentioned that said switches I02 and I03 are connected in a circuit to control the rate of feed of the vibratory conveyor 26 and when switch I02 has its contacts closed, the rate of feed of said vibratory conveyor 26 willbe reduced while, when switch I03 has its contacts closed. the rate of feed thereof will be increased. When the contacts of both of said switches are broken, the vibratory conveyor 26 willfeed inaterial to the conveyor 48 at a normal rate, which normal rate will be adjusted automatically in a 'manner hereinafter described in complete detail.

Before describing in detail the control circuit and control mechanism for the vibratory con-' veyor 26, it may be stated that said mechanism and circuit is so constructed and arranged that the vibratory conveyor 26 will feed material to the constant speed belt conveyor 48 of the scale mechanism 45, at a rate which is substantially that required to maintain the scale mechanism 45 in equilibrium. Upon a disturbance of the condition of equilibrium for a relatively short' period. therate of feed of said vibratory conveyor 26 will be either increased or decreased from its normal to compensate therefor. Should this condition of unbalance persist for a predetermined time,-then-automatic means are brought into operation to adjust thenormal rate of feed of the vibratory conveyor 26. As a consequence,

1 stant rate, and to compensate for any variations in the rate of feed of the vibratory conveyor 26 a which is necessary to maintain the constant feeding of the belt conveyor 48.

Attention is now directed to Figs. '7, 8 and 9 and to'the control mechanisms used'in conjunction with the electric control circuit. which will be described hereinafter. Said control mechanism comprises a control box I 25 within which is mounted a master switch I26 which may be controlled by a lever I21 extending outside the said control box I25. Said control box is also provided with a' pair of plug receptacles I28 and I29 adapted to receive terminal plugs of a common type. Also within the control box I25 is a pair of signal lamps I30 and I3I, a pair of screwof floating secondary transformer-relays I34 and I35. Also within said control box I25 is an adjustable auto-transformer I36 provided with an adjustable secondary tap which is controlled by a contactor carried on a rotatable shaft I31. Shaft I31 carries a large gear I38 withinthe control box I25 and also extends through the cover plate of said control box to receive an operating dial I39. The operating dial I39 may be adjusted to control the. secondary tap of the auto-transformer I36, thereby to adjust the seccndary voltage of said auto-transformer. Automatic adjustment-of said tap is also provided by a pinion gear I40 which meshes with the gear I38 and is carried on a shaft I4I mounted in appropriate bearings upon a bracket I42 and carrying a friction drum I43. Cooperating with the friction drum I 43 is a pair of oppositely extending pivoted levers I44 and I45 which are pivotally attached to' stub levers I46 and I41 respectively, which stub levers are pivoted about the axis of shaft I4I.

As illustrated in Fig. 9 of the drawings, when the level I45 is moved upwardly about its pivot pin I48 it forces a friction shoe I49 carried by a cup I45 thereof, into frictional engagement with the drum I43 and thereupon movement of the lever I41 on its pivot I4I causes a small increment of rotation of said drum I43 in a counter-clockwise direction. A reverse movement of the lever I45 will produce no rotation of the drum I43 due to the fact that it will cause the shoe I49 to lift from the periphery of said drum I43. The lever I44 will be provided with a cup I44 and ashoe I52 and when lifted upwardly will cause a small increment of rotation of the drum I43 in a clockwise direction. It will thus be evident that intermittent up and down movement of the lever I45 will cause intermittent counter-clockwise rotation of the drum I43' tent up and down movement of the lever I44 Will be effective to adjust the adjustable tap of the auto-transformer I36 to decrease the output voltage thereof.

To provide for the lifting of the levers I44 and I45 we provide a pair of solenoids I 53 and I54, respectively, having cooperating plunger or core type armatures I55, I56, respectively, which are pivotally attachedflto the ends of the levers I45 and I44 respectively by links I51 and I58, respectively. The means to efiect the intermittent operation of the solenoids I53 and I 54 will be described in connection with the electric circuit. It will be obvious that when a solenoid, such as" solenoid I53, is energized, it will lift its plunger I55 to swing the lever I45,'to the position shown in Fig. 9 as previously described, and when said solenoid I53 is de-energized, its plunger I55 and the lever I45 will move downwardly under the influence of gravity. It may also be mentioned that when both of said solenoids I53 and I54 are de-energized the drum I43 will be free to rotate and thus the output voltage of the auto-transformer I36 may be readily adjusted by the operating dial I38.

Attention is now directed particularly to Figs. 1, 10, 11 and 12 and to the electric circuit for controlling the constant capacity feeder. The circuits illustrated in Fig. are all containedin the control box I25 while the circuits shown in Fig. 11 are attached to a cable I59 provided with a receptacle plug I 66 adapted to be inserted'into receptacle I28 and leading to a control box I60 for the vibratory conveyor 26 and the electric motor 50 of the belt conveyor 68. Individual branch cables IN and I62 lead from the motor control box I60 to the field winding SI of the vibratory conveyor 26 and to the electric motor 50, respectively. Another cable I63, provided with a receptacle plug I65 adapted to be inserted into receptacle I28, leads to the switches I62 and I03 in switch box II. that receptacle plugs I64 and I65 may be readily detached from the control receptacles I28 and I29 carried by control box I25.

In addition to the elements previously described in connection with the control box I26, it may be mentioned that the master switch I26 is provided with a plug receptacle I66 (Fig. 8) to receive a plug from 'a commercial source of power such as the usual 60 cycle power mains, and also carries on its top a small pilot light I6I which is visible from the outside through a red paned window I68 to indicate whether or not power is being supplied .to the control circuit.

As seen in Fig. 10 of the drawings, power is supplied to the control circuit over a pair of power "mains I69 and III] which are controlled by master switch I26, across which mains is connected the pilot light I61, Connected directly across the mains I69 and I10 is the winding III of the autotransformer I36. Connected to power main I69 is a conductor I12 which leads to terminals H3 and I14 of the primary windings I and H6 of the transformer-relaysl34 and I35, respectively.

In the interest of clearness from an electrical viewpoint, we have shown in Fig. 10 of the drawings ordinary transformers with primaries III?) and I16 and separate relay solenoids III and I78 connected in circuit with the secondaries III! and I80, respectively, of the transformers. In actual It will be evident' practice, however, instead of the separate transdividual transformers and'individual solenoids, as

illustrated in Fig, 10, may be employed.

In addition to connecting the terminals I13 and I14 to the power main I69, the conductor I12 leads to socket terminal I8I of the socket I28 which is adapted to receive and make electrical connection with terminal I82 of the plug I64. (Figs. 2 and 11.) Terminal I82 (Fig. 11) is connected by conductor I83 to one terminal of the electric motor 50, the other terminal of which is connected to conductor I84, which, in turn, is connected to terminal I85 of plug I64. Terminal I85 of plug I64 is adapted to make contact with terminal I86 of socket I28 when the plug I64 is inserted into the socket I28, said terminal I86 being connected to conductor I81, which is permanently attached to or near one end of the winding "I of the auto-transformer I36. It will thus be seen that when switch I26 is closed and plug I64 is inserted in socket I28, a circuit will be-provided to the electric motor 50. This circuit is not altered by any of the control mechanisms and will be effective to drive the motor at a constant speed, said motor 50 being a constant speed type of alternating current motor, such as a synchronous motor.

tioned branch cable I62 includes the-conductors I63 and I84.

The circuit to -the electric motor 56 may be traced from the power main I69 through one side of switch I26, conductor I12, terminal -|8I,

terminal I82, conductorl63 to one terminal of motor 59, thence from the other terminal of motor 56 through conductor I64, terminal I65,

terminal I86, conductor I81, the endturns of winding "I of auto-transformer I36, to main I16 through the other side of switch- I26.

The-circuit for the field winding 3| of the vibratory conveyor 26 also includes the previously traced circuit from main I16 to terminal I65 of plug I64 over conductor I66 to one terminal of.

field winding 3|, thence over conductor I89 through switch I96 to terminal |9I of plug I64, thence to terminal I92 of socket I28, thence to conductor I93, control resistor I94, control resistor I95, conductor I96, to variable tap I91 of the auto-transformer I36, It may be pointed out that conductors I68 and I89 form the previously mentioned branch cable I6I.

It may be noted from the description thus far given that the field winding3I- of the vibratory conveyor 26 has two resistors I 94 and I95 connected in series therewith and the voltage supplied to the circuit for said field winding 3| may be varied by varying the position of the tap I91 of the auto-transformer I36. It may be mentioned that when the scale mechanism 45 is in a condition of equilibrium the resistor I 95 will be shunted by circuits hereinafter described, while resistor I94 will remain in series with said field winding 3|,

Should the equilibrium of the scale mechanism 45be disturbed by a lack of suflicient material onthe belt' conveyor 48, then resistor I94 will also be shunted out, thereby increasing the rate of de- Should the equilibrium be upset by too much material on the conveyor 46, then both resistors I '94 and I95 will be in series with the field winding 3| whereby to reduce the output of the vibratory conveyor 26.. Should either condition of dis turbed. equilibrium be maintained for a predetermined time, then the variable tap I91 of the autotransformer I36 should be properly adjusted to increase or decrease the voltage supplied to conductors I81 and I96, as the case may be, whereby to adjust the normal output of the vibratory conveyor 26 to a rate necessary to maintain the scale mechanism 45 in substantial equilibrium.

To provide for the control of the resistors I94 and I95 to determine whether only one or both, or

neither; will be in series with the field winding 3|,

depending upon'the condition of the scale mechanism 45, we provide the branch circuits now to be described. A shunt circuit for the resistor I95 is provided by conductor I98, mercury switch I99 ,and conductor 266. Mercury switch I99 is' normally closed and is carried on a pivoted plate 26I isconnected to conductor-I96 by conductor 264.

controlled by solenoid I16, or in practice, by the floating secondary I16 of the transformer-relay I35. 'I'herefore, with transformer-relay I35 deenergized, resistor I95 will be effectively short a conductor 262 which leads to normally open mercury switch 263,.the other. terminal of which ,Mercury switch'263 is-carried on pivoted plate 265 which is controllable by solenoid I11, or in actual practice, by a floating secondary coil I11 (Fig. '1) of the transformer-relay I34.

It will be evident that, as the pivoted plate 26I is pivoted about its axis by solenoid I16 or floating secondary winding I18, the normally closed shunt circuit around the resistor I95 will be broken and said resistor I95 will be inserted in the circuit of the field winding 3|, thereby reducing the rate of delivery of material by vibradirectly to the power mains I69 and I16 by-the previously mentioned. connection to terminals I13 and I14 and by a connection of terminals 266 and 261, respectively, to the conductor I61 over branch conductor 266. It will thusbe seen that the primaries I15 and I16 will be permanently connected across the power mains whenever master switch I26 is closed The circuit to solenoid I16 will be from te minal 269 of secondary I66 over conductor 2I6, terminal 2 of socket I29, terminal 2I2 of plug I65, conductor 2I3 of cable I63, to lead I69 of mercury switch I62, thence through mercury switch I62, to lead II6 thereof, to conductor 2I4 of cable I63, to terminal 2I5 of plug I65, to terminal 2I6 of socket I29, over conductor 2", solenoid I16, conductor 2I6, to terminal 2|9 of secondary I86. In the preferred modification it will be evident that, as has previously been mentioned, floating secondary winding I11 will take the place of solenoid I18 and transformer secondary I86. f I

The circuit for solenoid I11 will befrom terminal 226 of secondary I19, conductor 22I, terterminal 226 of secondary-|19, over conductor. 221.

It may again be mentioned that in lieu of solenoid I11 and secondary I19, we prefer to employ floating secondary winding I11. (Fig. '1.)

It will be evident from the. above traced circuits that, whenever the amount of material on the conveyor 48 falls below that required to maintain the scale mechanism 45 in balance,.mercury switch I63 will close its contacts with the consequent energization of solenoid I11 resulting in the closing of the contacts of mercury switch 263..

This will short circuit both of the resistors, I94 and I95 thereby increasing the rate of delivery of the vibratory conveyor 26 to supply material to the conveyo'r48 at a more rapid rate.

When equilibrium is re-established, both of the mercury switches I62 and I63 will have their contacts open and-only a circuit with the field winding 3| of the vibratory conveyor 26,-"due tothe fact that solenoid resistor I94 i111 be in.

' transformer-relays I34 and I35 will be connected I11 will be de-energized, and mercury switch 203 will be in open circuit position.

Should the equilibrium of the scale mechanism 45 be disturbed due to an excess of material on the conveyor 48, the mercury switch I02 will be closed, as previously described, with the consequent energization of solenoid I18 over the previously described circuit. This will tilt the plate 20I and open the contacts of mercury switch I99, breaking the normally closed shunt or short circuit around the resistor I whichincludes conductor I98, switch I99 and conductor 200. Resistor- I95 will 'then be inserted along with resistor I94 in series with the field winding 3| of the vibratory conveyor 26, thereby cutting down its rate of material delivery to the conveyor 48, thus resulting in the equilibrium of the scale mechanism 45 again being restored.

It is to be noted that the condition of pivoted plates 20I and 205 is an indicationoi the rate of delivery of the vibratory conveyor 26.

When both of said plates are in the positions illustrated in Fig. 10, said vibratory conveyor 26 will be delivering material at its normal rate with only resistor I94 in series with field winding 3| thereof. If plate 205 is tilted, vibratory conveyor 26 will, deliver material at an increased rate, while if plate 20I is tilted, it willdeliver material at a decreased rate, as previously described.

To indicate the rate of delivery 01' the vibratory conveyor 26, we provide mercury switches 228 and 229 carried by plates 285 and 20I respectively, which are normally open and which control signal lamps I30 and I3I, respectively. The circuit for signal lamp I30 will be from conductor I81 over conductor 230, lamp I30, conductor 23I, lead 232, the terminals of mercury switch 228, lead 233, to terminal I13 which is directly connected to power main I69, as previously described.

It will be evident that when plate 205 is tilted, switch 228 will be closed and lamp I30 lighted.

The circuit to lamp I3I is from conductor I31,

over conductor 230, lamp I3I, conductor 234, lead 235, to one terminal of switch 229, thence over the other terminal of switch 229, to lead 238, thence to terminal I14, which is also connected to main I69, as previously described. It will thus be evident that when plate 28I is tilted, switch 229 will be closed and lamp I3I lighted.

In parallel with lamp I30 we provide a circuit including'the previously mentioned solenoid I54 and a resistor type of biinker mechanism 231, which comprises a heating resistor 238 and a bi-metallic member 239, which, when heated for a predetermined time by heater 238, forms a shunt circuit therefor. A blinker mechanism 240, similar to the blinker mechanism 231, is also provided in a shunt circuit including solenoid I53. 4

Whenever mercury switch 228 is closed it. will not only illuminate lamp I30, but also will send current. through the heating resistor 238 and through solenoid I54. Due to the resistance of plunger I56 will be efiected to give one step to the variable tap I9l of the auto-transformer I36 in a direction to increase the voltage supplied to the conductors I96 and I81, which will, of course, increase the voltage supplied to the winding 3i of the vibratory'conveyor 26.

It will be evident that, if switch 228 remains closed for a relatively long time, blinker mechanism 281 will operate to cause an alternate opening and closing of the shunt of the resistor 238 with the consequent ratchet like action of the lever I44 producing continued step by step motion of the variable tap I91 to increase the voltage supplied to winding 3i. The blinker mechanism 240 will cooperate with the solenoid I53, under the control of mercury switch 229 to reduce the voltage supplied to the conductors I96 and I81 by shifting the variable tap I91 should said switch 229 remain closed for a prolonged period. It is thus evident that the control for the Vibratory conveyor 26 is entirely automatic and the voltage supplied thereto will be controlled by controlling the resistance of the circuit leading to the winding 3i thereof if only for a short period, but if for an extended period an additional control of the voltage supplied to the lines I96 and I81 will be effected.

In the operation of the device comprising our invention, the scale mechanism 45 will be brought to a condition of equilibrium by adjusting the weight 99 is set to deliver 200 pounds of a given conveyor 48 and with the weight 99. in its zero position, or along the fulcrum point of said scale mechanism 45. Weight 99 will then be set to any desired position depending. upon the rate of feed. of the material which is desired. In this connection it may be mentioned that for any given material the rate of feed will be constant for any fixed position of the weight 99.

Furthermore, a rather wide variation in the density of material to be fed will not alter the setting of the weight at 99. For example, if said weight 99 is set to deliver 200 pound of a given material an hour, an example of which may be soda. ash, this rate of delivery will be maintained constant even though the density of the material varies as .much as fifty percent. It has been found in practice that materials of widely different densities, such as sand and cork, the former of which has a density more than ten times that of the latter, the same setting of the weight 99 will not produce exactly the same rate 'of delivery, though the variation is not great.

delivery will be constant within measurable'lim its, and so long as the density does not vary more than fifty percent the .delivery rate will be substantially constant. I I

It is to be particularly noted that as the material is fed by the vibratory conveyor 26 to the belt conveyor 48, it drops on the sloping back plate 82, which has a tendency to form the material at a substantially uniform depth onthe belt 62. The belt 62 then'carries the material toward the fulcrum point of the scale mechanism 45.- This direction of movement is very important to reduce to a minimum the time required to bring the scale mechanism 45 to a stable condition. This is due to the fact that as the material is conveyed towards the fulcrum point the length of its lever arm decreases and thus the balancing torque thereof is progressively reduced. Without this progressive reduction in the balancing torque of the material it is very difficult to bring a constant capacity feeder into a condition of equilibrium, because there is a tendency for it to feed in batches. That is, material will be fed thereto until a certain weight is received sufficient to maintain a condition of equilibrium. The feeding conveyor will then be 'shut off entirely until this batch of material is completelydumped from the conveyor. As a consequence, the conveyor willbe practically empty and another batch will be dumped, this procedure being continuously repeated.

In the device herein disclosed, however,. the effective balancing power of the material is progressively decreased and in a relatively short time a stable condition of equilibrium is reached,

after which the feeder delivers material at a substantially constant rate. It has been found in practice that for practically any material it forms substantially equal depth through the entire length of travel thereof on the belt 62.

During the starting of the device into operation, the scale mechanism will go into and out of equilibrium, first to one side and then another, with a consequent operation of the control circuits of Figs. 10, 11 and 12 to increase or decrease temporarily the rate of delivery of the vibratory conveyor 26, and to determine automatically the normal rate of'delivery of said vibratory conveyor 26. After a relatively short period said vibratory conveyor 26 will be automatically adjusted so that when the scale 'mechanism 45 is in equilibrium it will be delivering material at substantially the same-rate that conveyor 48 discharges material. This is'a normal operating condition and any supply-fluctuations in the rate of delivery of the vibratory conveyor-26, which may be caused by voltage fluctuations on the line, or any other reasons, will produce a temporary increase or decrease in the rate of delivery thereof, as determined by the scale mechanism 45, thereby to return said scale mechanism 45 to a condition of equilibrium. As a consequence, a constant quantity of material will be discharged over the head drum 54-of the conveyor 48 and through the chute 80, notwithstanding fluctuation of main .line voltage. I

Attention is now directed to Fig. 13 of the drawings in which we have shown-a modified form of constant capacity feeder which is essentially a constant volume feeder. It may be mentioned that the previously described device is essentially a constant weight feeder and by proper adjustment the device of Fig. 13 may be converted from a constant volume feeder to a constant weight feeder.v As fllustrated in said Fig. 13, the only alteration in the system is in connectionwith the belt conveyor 48' which will follow the construction of belt conveyor 48 except for the differences specifically pointed out. Said belt conveyor 48' comprises a casing 245 adapted to provide an adjustable gate 246 having an upstanding threaded shaft 241 provided with a wing nut 248 'held in place by bracket 24!] and adjustable to adjust the size of an orifice 258 provided by gate 246, The weight 96 or the weight 99 is adjusted with reference to the specific gravity of the material 25| being conveyed and to the size of the orifice 258 so that said material 2 5| will form in a pile behind the gate 246. The control mechanism is adjusted so that the pile may have an average height, as indicated in Fig. 13.

It is evident that the belt of the conveyor 48,-

which travels at constant speed, will carry a constant-volume of material through the orifice 256 and the automatic control mechanism will operate to insure the presence of'suflicient material inthe pile behind, the gate 246 to maintain this constant flow of material 25!. It will be evident that by adjusting-the size of the orifice 250, as provided by wing nut 248, the volume of material delivered may be adjusted as desired. It is also obvious that by lifting the gate 246 to its maximum position, or to any position so that the orifice 250 is not completely filled with material at all times the device will be converted from a constant Wilume feeder to a constant weight feeder.

It is thus evident that, by employing the device as modified in accordance with the disclosure of Fig. 13, either a constant weight or a constant volume feeder may be provided, either of which may be embraced by the expression, "eonstan-t' capacity feeder.

It would alsobe evident that if the material 25], this condition will not be realized.

It should be particularly noted that while the adjustable weight'90, as shown in Fig. 3, is useful in balancing the scale beam including the conveyor 48, when the latter is unloaded, the weight 99 in association with the weight scale 98' is relied on to regulate the weight of the feed from the conveyor 48. The greater the distance of the weight 99 from the fulcrum 44, the greater will be the weight of feed of the/material from the conveyor 48. After once setting the weight 99 for a predetermined feed per minute, the delivery from the-conveyor 48 of a continuous stream uniform in weight, is automatically maintained. The automatic control is quite sensitive in that any variation of feed by the electric vibratory -feeder 26 will effect tilting of the scale beam in to the conveyor belt 62. If the weight of the material on the belt 62 falls below the amount predetermined by the settingof the weight 89, the rate of feed of the feeder 26 will be automatically increased. With the system of control shown in Fig. '10, whenever the scale beam is thrown out of balance, it is automatically brought back into balance so that the rate of feed by weight from the conveyor 48 will be automatically maintained. It-will thus be seen that the conveyor 48 is driven at a uniform rate of speed and the weight of materal on the belt 62 is maintained constant notwithstanding variations in the delivery from the hopper 33 or variationsin weight per unit of volume.

In the modification shown in Fig. 13 the volume of material fed from the conveyor 48, may

be maintained at a uniform rate. The volume is controlled by the gate 246 but the weight of the material on the belt 62 is automatically maintained constant because it can pile up as illustrated at. 25l in Fig. 13 in the nature of storage,

while the volume as predetermined by theadjustment of the gate 246, is being delivered from the discharge end of the conveyor 48' at a uniform rate of speed. It can readily be seen that by regulating the speed of the motor 50, the belt 62 may be driven at a constant predetermined speed, and a constant volume of material fed from the belt 82 in accordance with the setting of the gate 246, without causing material to pile up at 251 to such an extent as to overflow from' the opening 83.

However, as stated hereinbefore, it is preferred that the motor 50 shall be a constant speed electric motor such as a synchronous electric motor, but the speed reducer may be adjusted to predetermine the rate of constant speed of the vonveyor 48 in accordance with the desired rate of speed of feed from the conveyor 48.

While some materials of granular nature having free flow characteristics, may be delivered at a uniform rate in a continuously flowing stream, such rate of speed of feed cannot be automatically regulated according to conditions by the according to the densities and even the same kinds of material will have different rates of flow at different times dependent upon their moisture content and the sizes of the granules, and furthermore some materials may be coarse and others fine thus having varying rates of flow under varying conditions dependent upon the climate. flowing from the hopper 33 may be controlled by the gate 34 and the rate of feed from the pan 21 may be regulated by the manual control of the current strength in the magnet 3|, but the flow from the hopper 33 into the pan 21 will vary and this will result in variations in feed from the delivery end of the pan 21 if the vibratory feeder 26 alone is relied on. What is desired is a great refinement in regulation of the delivery by automatically controlling the rate of feed from pan 21 so as to lay down a uniform layer of the material onto the belt 62 at its receiving end and thereby assure a constant flow at a uniform rate of feed from the belt conveyor 48. In other words, when variations of delivery of the material to the belt conveyor 48 at its receiving end occur, the electric system controlled by the tilting of the scale beam will automatically increase or decrease the delivery to the receiving end of the conveyor 48 until such equilibrium is established that the feed from the conveyor 48 atits discharge endwill be maintained at a uniform rate of speed either as to weight in the form shown in Fig. 1, or as to volume and weight in the form shown in Fig. 13.

While the above described control system is particularly useful inconnection witha constant capacity feeder, it has other fields of usefulness to maintain a normal condition under the control of a widevariety of condition, indicators, to control the feed rate of a feeder and thereby maintain a substantially constant condition.

Obviously those skilled in the art may make various changes in the details and arrangement of parts without departing from the spirit and scope of the invention as defined by the claims hereto appended, and we therefore-wish not to be restricted to the precise construction herein disclosed.

To a certain extent the volume Having thus described and shown an embodiment of our invention what we desire to secure by Letters Patent of the United States is:

1. In a constant capacity feeder, the combination with a frame pivoted on a fulcrum, of a conveyor comprising a continuous belt and end rollers all carried by said frame, means for driving said conveyor at a constant speed and in a direction to convey material toward the fulcrum axis, adjustable means for balancing said frame about said fulcrum, a vibratory conveyor constructed and arranged to deliver material to said first mentioned conveyor, and means controlled by the balanced or unbalanced condition of said pivoted frame for controlling the delivery rate of said vibratory conveyor.

' said vibratory conveyor constructed and arranged to control it as determined by the balanced or unbalanced condition of said pivoted frame, to maintain said frame insubstantial balance.

3. In a constant capacity feeder, the combination with a frame pivoted on a fulcrum, of a conveyor mounted on said frame at one side of said fulcrum, saidconveyor comprising a pair of parallel drums, a continuous conveying belt carried by said drums, a feed chute leading to the outer end of said conveyor, a discharge chute leading from the inner end of said conveyor, a constant speed motor carried at the other side of said fulcrum, and, means connecting said motor and said conveyor whereby the latter will be driven by the former to convey material toward said fulcrum, at a constant speed.

4. In a constant capacity feeder, the combination with a frame pivoted on a fulcrum, of a conveyor mounted on said frame at one side of said fulcrum, said conveyor comprising a pair of parallel drums, a continuous conveying belt carried by said-drums, a feed chute leading to the outer end of said conveyor, a discharge chute leading from the inner end of said conveyor, 9. motor carried at the other side of said fulcrum, and means connecting said motor and said conveyor whereby the latter will be driven by the former to convey material toward said fulcrum.

5. In a feeder, the combination with a frame pivoted on a fulcrum, of a conveyor carried by said frame at one side of said fulcrum, said conveyor comprising a pair of drums, a conveying belt carried by said drums, a hood for the upper run of said belt comprising a receiving chute providing a material banking plate and a discharge chute, a motor for driving said conveyor, and means at the other side of said fulcrum adapted to balance said frame.

6. In a constant capacity feeder, the combination with a frame pivoted on a fulcrum, of a conveyor carried by said frame on one side of said fulcrum, means for driving said conveyor at a constant speed to carry material toward the fulcrum, means for balancing said frame about said fulcrum, a second-conveyor constructed and arranged to deliver material to said first mentioned,

conveyor, control means for said second conveyor constructed and arranged to control it under the ing from said transformer to the motor of said conveyor including a plurality of resistors, shunt circuits for each of said resistors, a scale, circuit control means operated responsive to the posi-' 'will be shunted, and when in a third position none of said resistors will be shunted. whereby the delivery rate of said conveyor will be controlled by said scale, and means operative in response to a sustained positioning of said scale from its normal position to adjust the output voltage of said variable transformer.

8. In a feeder, the combination with an electric conveyor, of a control circuit for said conveyor comprising a circuit leading to the motor of said conveyor including a pair of resistors, shunt circuits for each of said resistors, a scale, circuit control means operated responsive to the osition of said scale and so constructed and arranged that when said scale is in a predetermined normal position one of said resistors will be shunted. and when in another position both of said resistors will'be shunted, and when in a third position neither of said resistors will be shunted. whereby the delivery rate of said conveyor will be controlled by said scale.

9. In constant volume feeding apparatus, the combination with a scale beam frame. of a conveyor mounted thereon, a hopper mounted on said frame and having a material bank ng plate and a restricted opening for effecting constant volume of feed from said conveyor. means for supporting the beam frame in balanced condition during delivery of material to said hopper and feed of material from said conveyor. means for delivering material to said hopper. and means controlled bythe tilting of said beam frame for regulating said delivering means to cause feed from said conveyor to be maintained in constant volume.

10. In feeding apparatus, the combination with a receiving and feeding conveyor. of electro-magnetic means for controlling the feeding of. material thereto,- variable voltage means to control the rate of feed of said electro-magnetic means; electrical means for controlling said variable voltage means including a circuit having there n a blinker fo (led by a heating resistor and a heat responsive element for shunting said resistor, and constructed and arranged whereby said heating resistor will be periodically shunted when voltage is continuously applied thereto, thereby controlling said variable voltage means in steps, and weight responsive means for controlling the circuit to said blinker and electrical means.

11. In a feeder, the combination with a frame pivoted on a fulcrum, of. a conveyor carried by said frame at one side of said fulcrum, said conveyor comprising apair of end drums, a conveying belt carried by'said drums, a motor for driving said conveyor to move material toward said fulcrum, vibratory feeder means for feeding said conveyor at a point removed fromsaid fulcrum, and means operated by movement of said pivoted frame for controlling the rate of feed of said vibratory feeder means.

12. In a constant volume feeder, the combination with a scale frame pivoted on a main frame, of a constant speed belt conveyor including head and tail pulleys, a continuous belt and a hopper material banking plate and a restricted orifice controlling the flow of material from said hopper under the influence of said belt, and means oper-: ated by the unbalanced condition of said pivoted frame for maintaining material in said hopper above the top of said orifice.

13. In a constant capacity feeder, the combination with a belt conveyor, of means for driving said conveyor at a constant speed, weight responsive means operated continuously by the material on said' conveyor, a vibratory electromagnetic feeder for feeding material to said belt conveyor at a controlled rate, control means for said feeder operated by said weight responsive means, said control means comprising immediately responsive .means to increase or decrease the rate of feed of said feeder relative to a'selected normal rate as the weight of material on said belt conveyor increases or decreases relative to a normal load, and means operative responsive to a sustained operation of said immediately responsive means to adjust the voltage applied to said immediately responsive means.

14. In a continuous weighing apparatus, the combination-with a pivoted frame, of a conveyor including end drums and an endless belt all mounted on said frame, electro-niagnetic vibratory feeding means for feeding material to one end of said conveyor, means for driving said conveyor at a constant speed and in a direction to convey said material from the position at which it is fed toward the pivotal axis of said frame, and means controlled by the balanced and unbalanced condition of said frame for adjusting the feed rate of said feeding means.

15. In a continuous weighing apparatus, the combination with a pivoted frame, of a conveyor including end dmms and an endless belt all mounted on said frame, electro-magnetic vibratory feeding means for feeding material to one endof said conveyor, means for driving said conveyor in a direction to convey said material from the position at which it is fed toward the pivotal axis of said frame, and means controlled by tilting movement of said frame to adjust the feeding of said feeding means.

16. In feeding apparatus, the combination with an electro-magnetic feeder, means to control the rate of feed of said feeder in response to a variable condition including means for indicating a variable condition as normal or abnormal, means for adjusting the feed rate of said feeder to sustain approximately anormal condition comprising means immediately responsive to an abnormal condition to adjust the feed rate of said feeder, and electrical-means responsive to a sustained abnormal condition to adjust the voltage supplied to said immediately responsive means.

17. In a feeder system, the combination with an electric feeder, of a control circuit therefor comprising a variable transformer, a circuit leading from said transformer to said feeder including a plurality of resistors, shunt circuits for.

dicator, circuit control means operative responsive to the position of said indicator and so constructed and arranged that when said indicator is in a predetermined normal position one of said resistors will be shunted, and when in another position all of. said resistors will be shunted, and when in a third position none of said resistors will be shunted, whereby the delivery rate of said feeder will be controlled by said indicator, and means operative in response to a sustained positioning of said indicator from its normal position to adjust the output voltage of said variable transformer.

18. In a feeder system, the combination with an electric feeder, of a control circuit therefor comprising a circuit leading thereto including a pair oi resistors. shunt circuits for each of said resistors, an operating condition indicator, automatically operable circuit control means operated responsive to the position of said indicator and so constructed and arranged that when said indicator is in a predetermined normal position one of said resistors will be shunted, and when in another position both of said resistors will be shunted, and when in a third position neither of said resistors will be shunted, whereby the delivery rate of said feeder will bev controlled by said indicator.

19. In a constant capacity, feeder, the combination with a pivoted frame, of an endless conveyor mounted on said frame and movable therewith, means for driving said conveyor at a constant speed and in a direction to convey material toward the pivotal axis of said frame, a vibratory electro-magnetic feeder constructed and arranged to deliver material to said conveyor, and means to respond to a sustained abnormal condition as indicated by said indicator to adjust the voltage supplied to said immediately responsive means.

21. In a feeder system, the combination-with an electric feeder of the vibratory type, of a control circuit therefor comprising a plurality of resistors, shunt circuits for each of said resistors, an operating condition indicator, circuit control means operative responsive to the position of said indicator and so constructed and arranged that when said indicator is in a predetermined normal position one of said resistors will be shunted, and when in another position all of said resistors will be shunted, and when in a third position none of said resistors will be shunted, whereby the delivery rate of said feeder will be controlled by said indicator, and electrical means constructed and arranged to be operative in response to a sustained positioning of said indicator from its normal position to adjust the voltage applied to said resistors. 1

EARLE V. FRANCIS. JAMES A. FLINT.

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